﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Bai24_C_Sharp
{
    class Program
    {
        static void Main()
        {
            absDerived a = new absDerived();
            Console.Write(a.Add(5, 4));
            Console.Write(a.Mul(2, 3));
            absClass b = new absDerived();
            Console.Write(b.Add(5, 4));
            Console.Write(b.Mul(2, 3));

        }
    }
}
